Buggy code:
public class DOMUtil { protected DOMUtil ( ) { } public static void copyInto ( Node src , Node dest ) throws DOMException { Document factory = dest . getOwnerDocument ( ) ; boolean domimpl = factory instanceof DocumentImpl ; Node start = src ; Node parent = src ; Node place = src ; while ( place != null ) { Node node = null ; int type = place . getNodeType ( ) ; switch ( type ) { case Node . CDATA_SECTION_NODE : { node = factory . createCDATASection ( place . getNodeValue ( ) ) ; break ; } case Node . COMMENT_NODE : { node = factory . createComment ( place . getNodeValue ( ) ) ; break ; } case Node . ELEMENT_NODE : { Element element = factory . createElement ( place . getNodeName ( ) ) ; node = element ; NamedNodeMap attrs = place . getAttributes ( ) ; int attrCount = attrs . getLength ( ) ; for ( int i = 0 ; i < attrCount ; i ++ ) { Attr attr = ( ( Attr ) ( attrs . item ( i ) ) ) ; String attrName = attr . getNodeName ( ) ; String attrValue = attr . getNodeValue ( ) ; element . setAttribute ( attrName , attrValue ) ; if ( domimpl && ( ! ( attr . getSpecified ( ) ) ) ) { ( ( org . apache . xerces . dom . AttrImpl ) ( element . getAttributeNode ( attrName ) ) ) . setSpecified ( false ) ; } } break ; } case Node . ENTITY_REFERENCE_NODE : { node = factory . createEntityReference ( place . getNodeName ( ) ) ; break ; } case Node . PROCESSING_INSTRUCTION_NODE : { node = factory . createProcessingInstruction ( place . getNodeName ( ) , place . getNodeValue ( ) ) ; break ; } case Node . TEXT_NODE : { node = factory . createTextNode ( place . getNodeValue ( ) ) ; break ; } default : { <START_BUG> throw new IllegalArgumentException ( ( ( ( ( "can't<seq2seq4repair_space>copy<seq2seq4repair_space>node<seq2seq4repair_space>type,<seq2seq4repair_space>" + type ) + "<seq2seq4repair_space>(" ) + ( node . getNodeName ( ) ) ) + ')' ) ) ; <END_BUG> } } dest . appendChild ( node ) ; if ( place . hasChildNodes ( ) ) { parent = place ; place = place . getFirstChild ( ) ; dest = node ; } else { place = place . getNextSibling ( ) ; while ( ( place == null ) && ( parent != start ) ) { place = parent . getNextSibling ( ) ; parent = parent . getParentNode ( ) ; dest = dest . getParentNode ( ) ; } } } } public static Element getFirstChildElement ( Node parent ) { } public static Element getFirstVisibleChildElement ( Node parent ) { } public static Element getFirstVisibleChildElement ( Node parent , Hashtable hiddenNodes ) { } public static Element getLastChildElement ( Node parent ) { } public static Element getLastVisibleChildElement ( Node parent ) { } public static Element getLastVisibleChildElement ( Node parent , Hashtable hiddenNodes ) { } public static Element getNextSiblingElement ( Node node ) { } public static Element getNextVisibleSiblingElement ( Node node ) { } public static Element getNextVisibleSiblingElement ( Node node , Hashtable hiddenNodes ) { } public static void setHidden ( Node node ) { } public static void setHidden ( Node node , Hashtable hiddenNodes ) { } public static void setVisible ( Node node ) { } public static void setVisible ( Node node , Hashtable hiddenNodes ) { } public static boolean isHidden ( Node node ) { } public static boolean isHidden ( Node node , Hashtable hiddenNodes ) { } public static Element getFirstChildElement ( Node parent , String elemName ) { } public static Element getLastChildElement ( Node parent , String elemName ) { } public static Element getNextSiblingElement ( Node node , String elemName ) { } public static Element getFirstChildElementNS ( Node parent , String uri , String localpart ) { } public static Element getLastChildElementNS ( Node parent , String uri , String localpart ) { } public static Element getNextSiblingElementNS ( Node node , String uri , String localpart ) { } public static Element getFirstChildElement ( Node parent , String [ ] elemNames ) { } public static Element getLastChildElement ( Node parent , String [ ] elemNames ) { } public static Element getNextSiblingElement ( Node node , String [ ] elemNames ) { } public static Element getFirstChildElementNS ( Node parent , String [ ] [ ] elemNames ) { } public static Element getLastChildElementNS ( Node parent , String [ ] [ ] elemNames ) { } public static Element getNextSiblingElementNS ( Node node , String [ ] [ ] elemNames ) { } public static Element getFirstChildElement ( Node parent , String elemName , String attrName , String attrValue ) { } public static Element getLastChildElement ( Node parent , String elemName , String attrName , String attrValue ) { } public static Element getNextSiblingElement ( Node node , String elemName , String attrName , String attrValue ) { } public static String getChildText ( Node node ) { } public static String getName ( Node node ) { } public static String getLocalName ( Node node ) { } public static Element getParent ( Element elem ) { } public static Document getDocument ( Node node ) { } public static Element getRoot ( Document doc ) { } public static Attr getAttr ( Element elem , String name ) { } public static Attr getAttrNS ( Element elem , String nsUri , String localName ) { } public static Attr [ ] getAttrs ( Element elem ) { } public static String getValue ( Attr attribute ) { } public static String getAttrValue ( Element elem , String name ) { }

Fix:
throw new IllegalArgumentException ( ( ( ( ( "can't<seq2seq4repair_space>copy<seq2seq4repair_space>node<seq2seq4repair_space>type,<seq2seq4repair_space>" + type ) + "<seq2seq4repair_space>(" ) + ( place . getNodeName ( ) ) ) + ')' ) ) ;